8 Report on the Copper Ores of the Deoghur Mines. [No. 8. 



These ores and their constituents may be described as follows : — 



A. 

 The Bright Peacock ores. 

 This is the well known variegated vitreous copper ore of mineralo- 

 gists, which contains from 50 to 70 per cent, of copper. Our specimens 

 are in thin veins, of which the thickest is f (five eighths) of an inch 

 thick, but as some specimens appear to contain a larger proportion of 

 the poor yellow sulphuret, not more than 30 or 40 per cent, should be 

 expected from this ore in practice. It contains no silver. 



B. 

 Dull Peacock. This is a more ferruginous and earthy variety of the 

 former ore, and of course would give less copper. It is indeed scarcely 

 worth making a variety of. It contains no silver. 



C. 



Marbled Peacock ore. This is a variety which occurs marbled with 



green and red earthy mixtures. It runs (either at the termination of 

 the vein or at the surface ?) to a pale earthy gossan. It seems to con- 

 tain a promising proportion of silver. 



Second Group, Fahlerzen, or Grey Copper. 

 D. 

 Bull massive Grey Copper, 

 This may be described a dull grey, greenish grey, and liver-coloured 

 Fahlerz, the grey varieties sometimes shining with a micaceous or silvery 

 lustre on the fresh fracture, the liver-coloured ones slightly micaceous 

 also on the fracture but of a reddish-colour on the weathered or old 

 surfaces. It is a true Fahlerz as to appearance, but I found it to con- 

 tain, on an average from the pound taken for amalgamation of the grey 

 and liver-coloured sorts together, in 100 parts. 



Sulphur and a little water, 12.55 



Earthy silicates, 33.85 



Peroxide of iron, 8.33 



Lead, 10.00 



Copper, 32.70 



Silver, : 0.17 



97.60 

 Loss,. . . . 2.40 



100.00 



